Skip to main content

NC State Extension

Magnetic Soils

en Español / em Português
Español

El inglés es el idioma de control de esta página. En la medida en que haya algún conflicto entre la traducción al inglés y la traducción, el inglés prevalece.

Al hacer clic en el enlace de traducción se activa un servicio de traducción gratuito para convertir la página al español. Al igual que con cualquier traducción por Internet, la conversión no es sensible al contexto y puede que no traduzca el texto en su significado original. NC State Extension no garantiza la exactitud del texto traducido. Por favor, tenga en cuenta que algunas aplicaciones y/o servicios pueden no funcionar como se espera cuando se traducen.


Português

Inglês é o idioma de controle desta página. Na medida que haja algum conflito entre o texto original em Inglês e a tradução, o Inglês prevalece.

Ao clicar no link de tradução, um serviço gratuito de tradução será ativado para converter a página para o Português. Como em qualquer tradução pela internet, a conversão não é sensivel ao contexto e pode não ocorrer a tradução para o significado orginal. O serviço de Extensão da Carolina do Norte (NC State Extension) não garante a exatidão do texto traduzido. Por favor, observe que algumas funções ou serviços podem não funcionar como esperado após a tradução.


English

English is the controlling language of this page. To the extent there is any conflict between the English text and the translation, English controls.

Clicking on the translation link activates a free translation service to convert the page to Spanish. As with any Internet translation, the conversion is not context-sensitive and may not translate the text to its original meaning. NC State Extension does not guarantee the accuracy of the translated text. Please note that some applications and/or services may not function as expected when translated.

Collapse ▲

The negative ends of two magnets repel each other. The negative end of one magnet attracts the positive end of another magnet. This same idea affects the retention of plant nutrients in soil. Some plant nutrients are cations, which have a positive charge, and some are anions, which have a negative charge.

Soil particles are similar to a magnet, attracting and retaining oppositely charged ions and holding them against the downward movement of water through the soil profile. Soils with a strong charge have the ability to hold more nutrients.

Supplies

  • 1/2 cup bentonite clay
  • 6-volt or 9-volt battery
  • 2 wires with alligator clips
  • Glass jar or measuring cup
Let’s Do It!

Watch the video for a demonstration! If you prefer, you can try this at home with an adult.

  1. Thoroughly mix 1 part bentonite clay with 2 parts water.
  2. Attach one alligator clip to the negative post on the battery. Put the wire end into the soil slurry.
  3. Attach the other alligator clip to the positive post and put the wire into the soil slurry.
  4. Make a prediction about how the soil with react with the different wires.
  5. Wait for 45 minutes and then pull the wires out of the soil slurry.

If you prefer to do this activity yourself, ask an adult and use this PDF for instructions.

Talk it Over!

  1. Was your prediction correct?
  2. Which wire had the most soil attached to it? Why do you think this is?
  3. What does this mean for soil and its nutrient holding capacity?
  4. Would a soil with a greater negative charge be able to typically hold more nutrients?
  5. What do you think this means for managing your soil for growing plants?

Extra Reading 

Too Much of a Good Thing: Nitrogen Leaching

Just like magnets, negative charges repel negative charges. Soils with a high negative charge tend not to hold negatively charged nutrients. As a result, water moving through the soil profile will leach negatively charged nutrients, such as chloride, nitrate, and sulfate out of the root zone. This leaching can result in contamination of groundwater, streams, and lakes or have other environmental implications.